As many of its illustrious alumni as it can manage will descend on Chicago this weekend to celebrate the 50th anniversary of Second City — the troupe that spawned a classic sketch comedy TV series and launched the careers of countless comedians, from Gilda Radner and Bill Murray to Tina Fey and Steve Carell.

Two of its most famous member, Catharine O’Hara and Eugene Levy, are particularly looking forward to the reunion — and to sharing the stage again.

“I’m much more comfortable with him now than I ever was in the old days,” O’Hara admits, as she and Levy have gone on to be mainstays in Christopher Guest’s improvisation-inspired films, including Waiting for Guffman, Best in Show and A Mighty Wind, in which they played star-crossed folk singers Mitch Cohen and Mickey Crabbe.

The reunion special also doubles as a benefit for Second City’s alumni fund. “They set it up for alumni of Second City who are going through any sort of troubles in their lives and need some financial help,” O’Hara explains.

The prospect of reviving favourite characters from the past has its downside, Levy admits.

“We’re going to try and bring some of the wigs out of the mothballs,” Levy says.

“It’s kind of sad in a way, but fun in another — sad to see us now, trying to do the same thing.”

On Wednesday, Second City in Toronto hosts a free improv show featuring some of the alumni who have passed through its doors.